Starting means for internal-combustion engines.



APPLICATION .HLED' 056426, 1913.

lL WYGODSKY STARTING mamas FUR INERNAL colwusuom ENGINES.

stationary in gines,

.carri n d; angl,

STARTING MEANS FOR 0l? BALTIMORE, MARYLAND, fa CRlPl-'fdw .ASSGNDEL, BY MESNE ASSIGNMENTS, ilt

INTERNAL-COMBUSTIEON ENGINES.

.application filed inecember 26, .1.913.

To all whom t may concern.:

. Be it known that l., LEON lVYnoDsirY, a subject ot the oit New York, in the county ot' llew York and State of New York, have invented cert tain new and useful Starting,` Means tor lntern:il-Combustion Engines, of which the following is a specilication.

My invention relates to improvements in ineans for starting internal combustion engines, and it comprises ineans 'for forcing air or other combustioil-supporting tluid into the engine cylinder and means tor injecting` combustible material into such cylinder, together with a siinple and highly etlective device which holds the piston et the engine starting position, until a sutticient. pressure ot the air or other coinbustionsupporting` fluid behind. the piston has been reached, and then permits the ily-wheel of the engine to niove a lewv degrees only,

as a signal to Ithe engine.,attendant to inject fuel-huid into the engine cylinder, and then iinlocks the piston altogether. Other tea? tures of iny invention will be pointed out hereinafter.

The objects of iny invention are, to facilitate the starting; ot' internal conibustion ento inake it possible tor even very large single cylinder engines or multi-cylinder engines to be started by a single attendant without the necessity ot con'ipressing air to high 'pressure and without storing` such air, and with p 'aetically the saine ease with which a corresponding steam engine would be started, and to make the starting inech anisin very simple, also to cause the startinginechanisrn to indicate visually when a proper pressure has been reached in the engine cylinder.

l will now proceed to describe niy invention with reference to the accompanying;` drawings. and will then point out the novel features in claims.

ln the drawings:

Figure 'l shows a side elevation and oartial section ot an internal combustion engine provided with starting;` nieciianisin einliod'ying` ni'y invention.

Fig'. 2 is a. detail side elevation ot the locking device. ot this starting.; mechanism, portion of the iywheel of the engine being `shown in section, and such tiywheel Specification of Letters Patent.

Czar of llussia, and a resident Paten-ted dan. itl, Serial No. 808,900.

being indicated in a slightly different position than the position shown in Llig,

Fig. 2 shows a transverse section through the toggle joint of the locking device oit Figs. l and 2.

Fig. 3 -is a central vertical section. ot one Jforni ot' air pump which may be used, the section being taken at right angles to l.

Fig. st shows a central longitudinal section of a positively lockable check. valve which. is convenient for 'use as a part of the start-- ing mechanism'. r, ,5,- Fig. 5 is a detaili'i'lsectioa of the oil-pump of the engine, the section being taken through the center of the oil pump and at right angles to lig. l, and looking troni the rear of Fig. l.

Fig. 6 shows transverse vertical. section. through the air-admission and inain eirhaust valve chambers of the engine7 also showing; mechanism for operating said valves.

Fig. 7 is a fragmentary longitudinal section of the rear portion oi2 the engine cy. der, the section being1 taken through the center o'f the air admission and exhaust valve chambers. i'

Fig. 8 shows, on a scale smaller than Figs. 6 and T., a detail transverse engine cylinder through the center of the auxiliary exhaust valve, and also shows means tor operating said valve.

Fig. 9 is a detail side elevation and pan tial section on a scale larger than ltig. ll., of the mechanism tor operating` the supple mental exhaust valve, showing,A ineans tor shitting the cani-operated roller to one side or the other. v i

ln the drawings, l designates engine cylinder', i). (Fig. 6) the `piston, 3 con necting.;` rod, et the crank sha'it and .3 a die wheel on said crank shaft.

The engine cylinder is provided extended hollow rear head il within iv ie a combustion chainlier 7 (if, l), a suitalrle ai` admission valve tl and a inain exhaust valve tl and sniinlcniental enhanst valve l@ being` mounted 'in this rear head; als"w ignition rino; il and sprayer l), the ik, .tion

ring; being ot the tyi'ie covered in in v .item No. 1,076,615), dated ctober 2l., '.ttall, and the sprayer being ot the type covered by niy Patent lilo. Qll, dated Uctober it, 1910. A valve operating shait i3 is driven section -ot the tl ll.

il il from the crank shaft 4 by gears 1st and 15 so constructed as to revolve shaft 13 at half the speed of the crank shaft. Upon this shaft 13 there is a cam 16 arranged to operate a rocker 17 which operates the exhaustJv A designates the fuel pump and 22 a governoradjusted cam drivenvby shaft 13, and arranged to operate the fuel pump; the governor-adjusted cani, and fuel pump, being arranged substantially as shown in my Patents Nos. 971,954 and 1,015,115 and in my companion application filed December 26,

1913, Serial No. 808,899, noW Patent 1,166,508, and being arranged to inject oil i or other suitable fuel, at or about the end of the compression stroke or beginning of the working stroke, into the sprayer 12 and so into the combustion chamber 7. 23 designates the fuel supply pipe leading from the pump 21 to the sprayer 12.

As previously stated, means are provided for supplying air or other combustion-sup porting fluid, under pressure, to the engine cylinder, for starting the engine. In Figs. 1 and 3, 24 designates a reciprocating pump cylinder and 25 a stationary pump piston, of

an air pump for supplying air-or other conibustion-supporting Huid to the engine cy1inder and also to a suitable torch -for heating' preliminarily the ignition ring 11. W'ithout limiting myself to the use of any particular type of pump, I will state that the particu'- lar form of pump shown is convenient and suitable for the purpose. 26 designates a bell-crank foot lever forl movingthe compression cylinder 24 downward, 27 a spring for moving such cylinder upward, 28 an air admission valve, 29r a spring actuated 'disi charge valve in the head of the stationary piston 25, such valve arranged to discharge the compressed air into the interior reservoir 25il of the hollow stationary piston 25, and 30 a link to which the lower arm of lever 26 is pivoted; 31- a pipe for conveyingv air from this reservoir 25 to the torch 32 (see also Fig. 7) 32a a pipe for conveying conibustible (oil or gas) to said torch, and 33 a pipe for conveying compressed air from the pump to the combustion chamber 7 and so to the engine cylinder. AI preferably provide a spring,r loaded valve 33LL (Fig. 3) preventing discharge of air from reservoir 25"l into pipe 33 until after a certain pressure, sufcient intenta for the operation of the torch 32, has been reached in reservoir 25a; and I preferably provide a positively lockable check valve illustrated vin Fig. 4 and hereinafter described, for preventing back-flow of gas from the engine cylinder and combustion chamber into pipe 33, when an explosion in the engine cylinder occurs. f

The connection between the foot-lever 26 and the reciprocating cylinder 24 are such that during the early portion of the compression stroke, when theresistance to motion of the cylinder is small thel'everage is small,

' while near the end of the compression stroke,

when the resistance to motion of the piston is great, the leverage is great. Thereby a nearly uniform resistance to motion of the foot-lever is obtained; z'. e., the load on the foot lever is nearly uniform.

In starting mechanism such as herein deduce a charge of fuel. A pressure gage onl the pipe 33, or on the engine cylinder, is not.

an altogether satisfactory meansfor indieating when the desired pressure has been reached, partly because a pressure gage if connected to the pipe 33, will be affected by the necessarily intermittent discharge of the pump 24, while a pressure gage directly connected to the engine cylinder may be affected by the heat in that cylinder; and partly because engines will attimes require greater air pressure for starting than at other times.

I have found that the best means for indicating when the desired pressure'has been reached in the engine cylinder isa locking device which holds the piston stationary until the desired pressure has been reached,

then permits a very slight motion of the` piston (and, therefore, of thei'iy Wheel) as an indication that the desired pressure has been reached, and then holds the fly-Wheel and piston stationary until, following the injection of fuel into the engine cylinder, and combustion of such fuel, the pressure behind the piston increases very greatly; thereby causing the piston to move forward and the fly-Wheel to revolve; whereupon this positive locking mechanism should then go completely out of engagement with the flyf wheel. .t very simple and positively operating locking device such as referred to iS illustrated in Figs. 1 and 2, comprising a dog 34 adapted to engage a recess 35 in the ilywheel 5- a lever 36 pivoted to some stationary gesportion ot' the engine, and provided 'with a spring 3T tending to pressit forward, and

i toggle links 38 and 39 connecting the lever 36 and the dog 34:. The pressure exerted by spring 37 upon lever 36 is readily adjustable by means ot' a nut Ll() on the spring-rod All. N nts 40a serve as a stop for lever-36l against spring 3i', and serve to adjust the action of clog 3ft.

'ifi/hen the dog 3st first engages the end o recess 35 ot the flywheel the very end i2 of such pand-engages the end oit such recess, as indicated in` Fig. l. l/Vhen a sutiicient pressure has been pumped up, behind the engine piston 2, to inove the piston forward, the point of engagement of the tlywheel with the dog' shifts from the very point of the dog to a point i3 somewhat Jfarther back, as illustrated in Fi, Q; and owing to the shorter radius oi' point i3 than point 42, the pressure which was sutiicient to start the piston, with the dog 3J: in the position shown in Fig. 1, is not sutlicient to continuel motion of the piston with said dog in the position shown in Fig. Consequently, the motion of the ily-wheel is through a `very few degrees only, but such inotion is sutiicient to be noticed h v the engine attendant, who thereby understands that suiicient pressure has been reached in the engine cylinder for the starting of the engine. lhe ignition ring l1 having previously heen heated to a temperature sul'licient 'to ignite an enteringcharge of fuel (such preheatingF having been effected by means of the torch 32) the engine attendant thereupon operates the fuel pump '2l by means of the hand lever 44- so injecting a charge of fuel through the sprayer l2' and past the ignition ring l1 into the combustion chainber 7, and since this combustion chamber is already tilled with air under considerable pressi-e the fuel so injectedv will immediately :nite and thereby greatly increase the pressure within the combustion chamber T and engine cylinder l, thereby starting the fine piston 2 forward against the resistance oii'ered by the dogg, 34, and forcing the lever 36 back against the pressure ot spring,I 3'? until the toggle 38-39 reverses, such reverse position being indicated in dotted lines in l. In the reverse position o't the toggle 355-39 the dog; is completely out ofi-engagement with the fly wheel., and will rei out of such engagement durnrt;1 the, .ned operation of the engine. its a. e 'init-ent means for resetting the doe; Se, the engine has stopped, i ins-,"e, the connecting pin 4:5 of the toggle 38-39 reniovrdrle.A TWhen the toggle is in the reverse j iosition, indicated in dotted lines in Fig. l., he mere removal of this pin #t5 inaltes it ossible to swing the parts of the toggle the position shown in full lines in Fig. l 'Hlm o wheei I having, ust been moved mechanism is until its 35 is opposite the nog 3a) and then, upon reinsertion o't' the pin 4:5, the toggle locking mechanism is connected up ready for use', and this resetting of the togaccoinplished, it will he seen, without ino'venient oi' the lever 3G against the pressure o spring 3i". Ot

course, the toggle mechanism might be reset by forcing the lever 3G backward; but this would involve considerable etort, particularly in the case ot` a large engine; whereas by the incre removal oif the pin '-t it is possible to reset the toggle without forcing back the lever 3G, and therefore it is substantially as easy to reset the toggle in a very niain exhaust 'valve i),

large engine, as 1n a small engine.

Upon `valve-cani shaft 13 there are two :ams 6l and (31*L adapted to engage an antifriction roller (32 (Figs. l and 8) on a follower lever el? connected to the stein of the supplemental exhaust valve l0. L spring (i3 4tends to hold valve l() closed. Cain 6l is arranged to engage, roller (52 to open valve l0 slightly in advance of the opening of the so releasing pressure in the engine cylinder just before the, inain exhaust valve opens, and thereby makingl it easier to open such ina in exhaust valve. in the noruial position of roller (i2, shown in Fig; l, cani Gl does not engage roller (i2 at all: but as shown in Fig. 9 this roller o2 may be nio'ved laterally to a position in which it will be engaged both by cam 6l and cani Gln. nd cano (31 is so located and proportioned as to open valve l() and hold it open during' a portion of thel conipression stroke oil the engine/piston, thereby 1 cseure, and so facilitating; the starting/oi the engine.

reducing' the coimpression'1 i other to which it may be adjusted, two holes (32a and (i2-b are provided in the axle about which this roller rotates, and a pin 62 is provided which may be thrust through either ot these holes, thereby holding the roller (S2 in one lateral position or the other.

'llhe starting of the engine by the ineens hereinbeiore described, is accomplished as Vfollows: ,l

if the engine tly wheel has not been stopped in the starting position such iiy wheel is turned over by hand, until just below starting position, and such turning over is facilitated by opening,l the auxiliary exhaust valve, itl, wlfiicn then operates as a release viftiife, l1 or so opening the auxiliary eithaust Vmire il provide a bandi-,lever t3 (l (i and 8) which, when raised, depre. es the operating lever et this release valve lo, so openingl valve. lllhen the ily wheel has been moved around 'to just below sta rting,y position, the release valve l0 is closed. the pin 45 removed from the toggle and the dogl 3tlreset in the recess 35 of the fly wheel and, the pin i5 again inserted.

Miti

, The roller 62 of the valve mechanism of the supplemental exhaust valve l0, is then Shiftedto the position shown in Fig. 9, in which it will be engaged by the cam 6l, The pump lever 2G is then operated to supply air under pressure for the operation of the torch 32, the operation of the pump compressing air into the reservoir 25a of the pump. At first air is discharged from this reservoir through pipe 3l only to the torch; but very soon a suilicient pressure is reached within this reservoir to openthe valve 33, whereupon the compressed air in excess of thatl required for the torch passes through pipe 33 into theveombustion chamber and engine cylinder. The escape of such excess compressed air through pipe 33 serves to maintain'within the reservoir 25 a substantially uniform pressure for the operation of the torch. The air passing over into the combustion chamber and engine cylinder will soon reach a pressure sufficient to move the piston forward slightly, bringing the bottom of the recess 35 of the fly wheel into engagement with the end 42 of the locking dog 34, and so bringing the piston accurately to starting position. The fly wheel and piston will remain in this position until air has been compressed to a suitable higher pressure within the combustion chamber and .engine cylinder to overcome the pressure of spring 37 exerted through the toggle links 38-39 and dog 34, and to move the ily wheel from the position shown in Fig. l to the position shown in Fig. 2.

By the flame of the torch 32 the ignition ring is very quickly heated to a temperature 'suflicient to ignite an\incoming charge of fuel. In practice, I have found that the ignition ring is so heated by the torch within from thirty to sixty seconds, and preferably I make the air pump of such capacity, that such pump, operated at aconvenient rate, will have compressed air within the engine cylinder to an extent sufficient to move the fly wheel from the position shown in Fig. l to the position shown in Fig. 2, by the time the torch has heated the ignition ring Sulliciently to ignite an incoming charge of fuel. Exact accuracy in this respect is not required, as it does no harm to heat the igni- 4 tion ring somewhat beyond the minimum temperature at which it will ignite an incoming charge; but reasonable accuracy in this respect is readily attainable, for different engine attendants will operate a foot lpump such as shown at nearly the same rate,

eing the natural rate of movement' of the foot,which does not differ greatly with different people, and therefore it is easy to so coordinate the capacity of the air pump, the heatingr capacity of the torch 32 and the rate of heating of the ignition device 1l, that by the time the ignition device ll is suiiieicntly het to ignite an incoming charge of fuel, or

very shortly thereafter, suicient pressure will have been reached in the combustion. chamber 'and engine cylinder to move the fly wheel from the position shown in Fig. 1 to the position shown in Fig. 2, in which latter position the ly wheel will be arrested owing to the shorter radius of the point 43 at which the fiy wheel now engages the dog 34, and therefore, `the still greater pressure required in the engine cylinder to move the iy Wheel beyond this second point of arrest. Thev movement of the tiy wheel from the position shown in Fig. l to the position shown in Fig. 2, though slight, i's sufficient to attract the attention of the engine attendant, and the ignition ring 11 having by this time become heated sufficiently forv ignithe sprayer 12 and past the ignition ring 11 y, into thecombustion chamber 7, and such charge of the fuel immediately ignites in the compressed air already Within that c0111-, bustion chamber, and the resulting' increase in pressure behind the en ine piston 2 moves the piston and Hy wheel forward against the resistance of the dog 34, reversing the toggle 38-39, and so automatically disengaging' the dog 34 from the fly wheel.

, lhe impetus so imparted to the engine piston 2 and fly wheel 3 by the introductionl and ignition ofthe first charge of oil, -will in many cases be suflicient to carry the engine throughout one expansion, exhaust, air admission, and compression cycle; i. e., two revolutions of the fly wheel. The next injection of oil will take place automatically by the automatic operation of the fuel pump 2l by cam 22, which new charge will be ignited by the ignition ring 11, and thereupon the engine will continue in its cycle, and it is no longer necessary to operate the air' pump 24 or the torch 32.

These operations required for the starting of the engine are very easily and simply and' quickly performed, and in practice the engine starts as easily and about as as if it were a steam engine.

The pressure of the spring 37 may be regulated, by means of the nut 40, so that any quickly particular desired air pressure in the cylin- (32 is shifted back to normal position so that the half compression camela no longer engages it and the valve 10 is no longer opened 'again operate the nessuna during the compression stroke; full coinpression being then reached in the engine cylinder.

Ylhile it is convenient to employ a half Compression cam G1 and means operated thereby for decreasing compression pressure during the starting of the engine, it will of course be understood that such half com# pression cani and means operated by it is not necessary for the starting of the engine. ln case no half compression cam is provided sufficient pressure must be pumped up in the combustion chamber during the pres liminary starting operations, and sutlicient fuel must be injected into the combustion chamber for the first explosion, to supply sufficient energy to carry the piston nearly through, and preferably completely through, the compression stroke, so that the engine will function automatically after such compression stroke is passed. Should the engine attendant see that the piston will not completely pass through the compression stroke, he may oper"L te the oil pump just before, or just as, the piston comes to rest, so starting the piston forward again and starting the ily wheel in backward rotation; and during this backward rotation the engine exhausts through what is normally the air admission valve, 8, and draws in air through what is normally the exhaust valve 9. hi ear the end of the compression stroke in reverse rotation (the stroke that would be the expansion or working stroke in normal operation) the engine attendant will fuel pump, producing a stronger explosion in the engine cylinder, and so starting the piston forward and start: ing the fly wheel in forward rotation; and the impetus thus imparted to the fly Wheel will be, in general, sullicicnt to cause the engine to function automatically thereafter; otherwise the operations of starting the engine in reverse rotation and starting it again in lei ward rotation, may be repeated.

llt will, of course, be understood that the compressed air for starting and for operation of the torch 32, may be supplied from any other convenient source instead/of the foot pump 24; and, in a broad sense, this foot pump constitutes a diagramnfatic representation of any suitable source of compressed air or other combustion-supporting Huid. p

To prevent the gases of the engine cylinder from passing back through pipe 33, into the reservoir 80, l preferably provide a spring 'actuated check valve 48 (Fig. 4L) which the air forced through 'pipe 33 opens against the lpressure of the valve spring lif); such valve being mounted within a bushing suitably secured in the side wall of the combustion chamber 7. As in injection en* ginesthe compression pressure is preferably moderately high (say from two hundred f 'pressure near and fifty to three hundred pounds per square inch) it is desirable that this check valve be closed positively once the engine is in full operation; and therefore for this pur pose l provide a hand wheel 5l having a screw thread connection with the 'end of the bushing o0 and also having a shoulder 52 engaging a collar 53 on the stem of the valve d8. lt will be apparent that by rotating this hand wheel il the valve i8 may be drawn up tightly against its seat, or may be released so as to be opened, against the action of its spring ll), by air under pressure forced in through pipe j .lhe shoulder 51.1? of hand wheel 5l is arranged to form a tight joint with the shoulder 5l" of bushing 50 when hand wheel 5l has been turned to release the valve titl to permit it to open, This prevents escape of air and gases through the screwthreath ed joint between the hand wheel 51 and the bushing 50.

l do not in this application claim the novel engine frame herein illustrated but nouspecifieally described, as the saine is claimed in my companion application filed December 26, 1913, Serial No. 808,895, non' Patent No. idle-,917, dated October E2G, lfllel. l dofnot in this application claim the auxiliary or supplemental exhaust value l0, and the means for operating it, as the saine claimed in my companion application docket filed December E2G, 1913, Serial No. 803,901@ now Patent No. 1,156,123, ldated October ll/l, 1915, itself a division of my application No. TbO. rlhis supplemental eathaust valve constitutes a very convenient means for' stopping the engine in the starting position. ln stopping an engineA of this type the com mon practice is to cut off the supply of fuel, .after which the fly wheel continues to rotate for some time, due to the inertia it has acquired, unt-il finally the inertia` of the liy wheel is unable to overcome the compression the end of the com'aression stroke of the piston. The fly wheel. then comes to rest, but immediately starts in backward rotation, due to the expansion of the air compressed within the cylinder, and rotates backward until the piston again compresses air in the cylinder. rl`he inertia of the 'fly wheel being, of course, insufficient to enable the piston to complete this backward compression stroke, said piston comes to rest near the end of such strok g and if,

just as the piston so comes to rest, the auxil iary valve lO is opened, by raising the lever 4G, so releasing the pressure within the engine cylinder, the piston and fly wheel remain in such position with the parts of the engine in about the proper position for starting. The hand lever 4G is provided with a cam portion which, when the hand lever is raised, depresses a push rod 5G against the action of a spring 57, this push l til l lili in dotted lines in Fig. l, to the engaging vsition shown 1n full hnes in Fig. 1, manually rod engaging a pin 58 projecting from the lever 47 engaging the stem of the auxiliary exhaust. valve 10.

The supplemental exhaust valve 10A and the two cams 6l and 6l, the one for oplen-A ing the valve 10 prior to the opening ofthe main exhaust valve, and the other for open ing the valve 10 during a portion of the compression stroke, are claimed in my companion application, Serial No. 808,901, now Patent No. 1,156,123, dated @ctober l2, 1915, and therefore are not claimed herein. rlhe valve l0 has many functions besides that of facilitating the turning over of the engine during the starting thereof.

1While I have illustrated and described the engine as provided with a foot operated air pump for compressing air in the engine cylinder, it will be obvious that, inthe case of small engines at least, it is practicable to dispense with such separate air pump and to compress air in the the iiy wheel, manually or otherwise, and thus compressing air within the engine cylinder by the action of the engine piston 2, the piston being stopped at the starting position and held there, until the injection of the fuel by the piston-holding means of which the dog 34 is a part. In. the case of a small engine particularly, it is entirely practicable to throw the piston holding means from the disengaged position shown or otherwise, and without removing the toggle pin 45; and when the air for starting the engine is to be compressed within the engine cylinder by motion of the engine piston 2, this piston holding means will commonly be thrown into engaging position without removal of the toggle pin 45. `What I claim is 1- l, In an internal combustion engine, the combination with an engine cylinder and piston, means for introducing air into said cylinder and -means for introducing fuel into said cylinder, at the vill of the operator, said cylinder provided with ignition means arranged to ignite such fuel at enn trance, of means for holding said piston stationary until the admission and ignition of the fuel, such piston-holding means are ranged to release the piston automatically after a predetermined pressure in the cylinder has been reached.

2. .ln an internal combustion engine, the

combination with an engine cylinder and piston, means for compressing air in said cylinder and means for supplying fuel to said cylinder, after the compression of the air therein, said cylinder provided with ignition means adapted to ignite a charge within said cylinder irrespective of the position of the engine piston, of means for holdin@ sadpiston stationary untilr a predetermined predetermined cylinder by turningV PFGSSUI@ IMS been reached in the engine cylinder, such piston-holding means arranged to' release the piston automatically after a pressure in the cylinder has been reached.

3. 1n an internal combustion engine, the combination With an engine cylinder and piston, means for compressing air in said cylinder at the will of the operator, and means for injecting fuel into said cylinder after the compression of the air therein,'said cylinder provided with ignition means adapted to ignite such fuel immediately upon the injection thereof into such cylinder, of means for holding said piston stationary until the fuel so injected is ignited,

such piston-holding means arranged to release the piston automatically after a predetermined pressure in the cylinder has been reached.

4. In an internal combustionA engine, the combination with an engine cylinder and piston, means for introducing air into said cylinder and means, including a fuel pump operable at the will of the operator, for inj ecting fuel into said cylinder, said cylinder provided with. ignition means adapted to ignite fuel so injected upon entrance to the engine cylinder', of means for holding said piston stationary until the injection and ignition of such fuel, such piston-holding means arranged to release the piston automatically after'a predetermined pressure in the cylinder has been reached.

o. fn an internal combustion engine, the combination with an engine cylinder and piston, crank shaft, and connecting rod, of a locking member adapted to engage a portion of the engine movable with said piston and thereby to hold the piston stationary against pressure against said piston, a toggle mechanism arranged in one position of the toggle to hold said locking member in en gaging position and in a reversed position of the toggle to hold saidlocking member out of engaging position, and means resisting motion of the toggle from engaging to disengaging position of the locking member.

6. In an internal combustion engine, the combination with an engine cylinder and piston, crank shaft and connecting rod, of a locking member adapted to engage a portion of the engine movable with said piston and thereby to hold the piston stationary against .pressure against` said piston, a toggle mechanism arranged in one position of the toggleA to hold said locking member in engaging position and in a reversed position of the toggle to hold said locking. member out of engaging position, and spring means resistingmotion of the toggle from engaging to chsengaging position of the locking member.

v7. ln an internal combustion engine, the combination with an engine cylinder and 

